Multiple flour sieve



3 Sheets-Sheet 1 Filed May 10, 1955 ATTORNEY.

June 23, A: 1 CLARK MULTIPLE FLOUR SIEVE Filed May 10, 1955 5 Sheets-Sheet 2 c 4 /dc a m fw mkfa aim fa 9 A. 1.. CLARK MULTIPLE FLOUR SIEVE 5 Sheets-Sheet 3 Filed May 10, 1935 I INVENTOR. Y Z

Patented June 23, 1936 MULTFPLE FLOUR. SIEVE Arthur L. Clark, Detroit, Mich.

Application May 10, 1935, Serial No. 20,774

5 Claims.

The object of my invention is to produce a flour sifter designed for re-sifting the flour several times at one sifting operation.

Another object is to produce a multiple flour sieve constructed with both rotating and oscillating agitating members all actuated by the same turning crank.

A further object is to produce a multiple flour sieve simple in construction, easily and efiiciently operated and that can be manufactured at a very low cost.

These several objects are attained by the construction and arrangement of parts more fully hereinafter set forth.

Similar parts on all drawings are marked by similar numerals or letters.

Fig. 1 is a front view of my multiple flour sieve showing the general arrangement of the operating mechanism.

Fig. 2 is a top view of the sieve showing the rotating agitator mounted within the casing top, and the relative position of the various operating parts.

Fig. 3 is a vertical sectional view lengthwise through the sieve casing taken on the line 3-3 of the Fig. 1, showing the multiple sieve arrangement with their respective agitators mounted therein.

Fig. 4 is an elevation of a modified form of triple rotor agitator, constructed of pressedsheet metal,

as may be substituted for the double rotor shown in the Figs. 1, 2 and 3.

Fig. 5 is also an elevation of a similar modified triple rotor agitator constructed of curved wire sections similar to the design shown in Fig. 4.

Fig. 6 is a plan. of a modified form of double oscillating agitator constructed of pressed sheet metal, as may be substituted for the single type shown in the Figs. 1, 2 and 3.

Fig. '7 is also a plan of another modified form of double agitator formed of curved wire sections, in similar design to that shown in the previous Fig. 6.

Fig. 8 is a vertical sectional view lengthwise through the casing, also taken on the line 33 of the Fig. 1, showing a modified arrangement of the multiple sieve agitators, all being oscillating members.

Fig. 9 is an elevation of a modified form of driving unit, substituting an eccentric driving unit in place of the crank shown in the Figs. 1, 2 and 3.

It is known that there are various other types of multiple flour sieves, but not of the mechanical construction and operation herein described and claimed.

In general, my device comprises a tubular casing member provided with a series of nested cup shaped sieve sections positioned therein, one beneath the other, equally spaced and each cup sieve provided with an agitator member for automatically working the flour therethrou gh, all agitators being connected together by a suitable mechanical unit and actuated by a single crank.

I will now describe more fully the detailed construction of my device, referring to the drawings and the marks thereon.

The casing I is made of thin sheet metal, preferably of tinned surfaces, and formed in an elongated tubular section, open at both ends. Through the central and lower sections of the casing is formed a series of ring wall grooves a, pressed or rolled therein, equally spaced along the tubular casing walls and positioned at right angles to the casing axis. A suitable handle member 2 of any desired design or construction is mounted on the casing side wall and fixedly attached thereto, providing means for conveniently lifting and holding the multiple sieve while operating same. Within each ring wall groove (1; is mounted a cup sieve 3, preferably of a spherical segment design, said cup sieve being made of a suitable fine mesh screen g and provided with a circular spring wire rim I) made integral therewith, designed for expanding to engage and fit the respective casing wall grooves a. when pressed therein, the expansion spring wire rim exerting sufficient pressure for rigidly retaining the cup sieves in a fixed position within their respective casing grooves. Directly above the upper cup sieve 3 is a rotor fiour agitator A, formed of curved arms c and provided with end bearing members (1 and c, said rotor 4 being positioned diametrically across the casing l and rotatably mounted therein through suitable wall bearing openings f. The agitator arms are each curved to the sameradius as the adjacent spherical segment cup sieve 3, and preferably positioned to nearly form a contact with the sieve screen surface as the agitator 4 is rotated thereover. One end bearing e is extended beyond the casing wall and formed with a drive crank section h and a turning crank it, all made integral therewith. Directly above each of the remaining cup sieves 3 is mounted a special oscillating agitator 5, also formed of curved arms 0', single or double, and provided with end bearings m and n, said agitators all being positioned diametrically across the casing I in the same vertical plane with the rotor agitator 4, and are rotatably mounted therein through suitable wall bearing openings p. Each of the agitator arms 0' being curved and formed as in the former case, to a radius corresponding to the adjacent cup sieve, and is positioned to nearly form contact therewith as the respective agitators are oscillated thereover, One end bearing 11 of each agitator 5 is extended beyond the casing wall and formed with a crank-arm r, all designed and positioned in alignment with each other, and connected together with a, crank bar 6 rotatably mounted thereon, capable of oscillating all agitators 5 in unison. The upper end of the crank bar 6 is connected to the crank it of the rotor agitator 4, by the pitman arm I pivotally mounted thereon, said pitman '5' being of a length to position the connected series of oscillating cranks r to nearly their extreme upper and lower positions, as indicated by the dotted lines 1, as the crank it is rotated through its extreme upper and lower positions. The rotor crank it is made of a slightly shorter radius than the connected oscillating cranks r, allowing continued rotation of the agitator 4, but reversing the cranks r before they reach their centers of rotation, causing the agitators 5 to oscillate back and forth within their respective cup sieves. This construction allows the several cup sieves to be placed very closely together and without interfering with the agitator members, and which would be impossible if all rotating agitators were used.

If desired, the rotor 4 may also be constructed with triple arms 0, or any other number, as illustrated in the Figs. 4 and 5 of the drawings. Also, the oscillating agitators 5 may be made of the double arm construction, either of pressed sheet metal or wire designs as illustrated in Figs. 6 and 7. The actual design of formation of either agitator is not material to my invention and it may be altered as desired.

It is apparent that my device is subject to various modifications in both arrangement and mechanical design without departing from the spirit of my invention, and I claim not only the multiple sifter as herein illustrated but also any modification thereof that is substantially a substitution of parts or combination of units therein shown.

Having fully described my multiple flour sieve, what I claim as my invention and desire to secure by Letters Patent is:

l. A multiple flour sieve, comprising an elongated hollow casing, open at both ends and having a series of cup sieves fixedly mounted crosswise therein, one above the other, a flour agitator mounted above each of said cup sieves and projected therein, designed to engage and oscillate along the res ective sieve surfaces, said agitators being formed with end crank member and positioned all in vertical alignment within the casing, crank means rotatably mounted on the casing positioned in alignment with the series of flour agitators, and means mounted thereon for connecting said crank to all of the agitators, capable of oscillating said agitators on their respective mountings as said crank is rotated.

2. A multiple flour sieve, comprising an elongated tubular casing open at both ends, a series of cup sieves of fine mesh, uniformly spaced and fixedly mounted crosswise therein, one above the other, a flour agitator mounted above each of the cup sieves and projected therein, all arranged in vertical alignment within the casing and designed to engage and oscillate along the respective sieve surfaces, each of said agitators being formed with an extended crank arm at one end thereof, crank means rotatably mounted on the casing in alignment with the flour agitators, and means for connecting said crank with the extended crank arms of the respective flour agitators, capable of oscillating said agitators on their respective mountings as said crank is rotated.

3. A multiple flour sieve comprising a tubular casing open at both ends and provided with a series of cup sieves of fine mesh screen fixedly mounted thereacross, one above the other, a rotor flour agitator rotatably mounted crosswise the casing above the top cup sieve and projected therein, designed to engage and rotate along the sieve surface, said rotor agitator being formed with an extended eccentric drive crank and connected turning means, an oscillator flour agitator rotatably mounted above each of the remaining cup sieves and projected therein, designed to engage and oscillate along the respective sieve surfaces, each oscillating agitator being formed with an extended eccentric crank arm at one end thereof, and means for pivotally connecting said rotor agitator drive crank to the extended crank arms of all of the oscillator flour agitators, capable of oscillating same in their respective mountings as the rotor agitator is rotated.

4. A multiple fiour sieve comprising an elongated tubular casing open at both ends, a series of cup sieves of fine mesh uniformly spaced and fixedly mounted crosswise therein, one above the other, a rotor flour agitator rotatably mounted above the top cup sieve and projected therein and designed to rotate along the cup sieve surface, said rotor agitator being formed with an extended excentric drive crank and connected turning crank, an oscillator flour agitator rotatably mounted above each of the remaining cup sieves and projected therein, all positioned at right angles to the casing axis and in vertical alignment with the rotor agitator, said oscillator agitators being designed to oscillate along the respective cup sieve surfaces, each of said oscillating agitators being formed with an extended eccentric crank arm at one end thereof, all positioned in alignment with the rotor agitator crank, a crank bar pivotally mounted on the'oscillator crank arm ends connecting same together all in one operating unit, and a pitman bar pivotally connected between said crank bar and the rotor agitator drive crank, capable of oscillating all of said connected agitators as the rotor agitator is rotated.

5. A multiple flour sieve comprising a tubular casing open at both ends and formed with a series of uniformly spaced ring grooves along the casing wall all positioned at right angles to the casing axis, a cup sieve of fine mesh sore-en fixedly mounted in each of the casing ring wall grooves, a flour agitator mounted above each of said cup sieves and projected therein, designed to oscillate along the respective cup sieve surfaces, each agitator being formed with an extended eccentric crank arm at one end thereof, all positioned in vertical alignment with each other, a crank bar pivotally mounted on said agitator crank arm ends connecting same together all in one operating unit, an excentric drive crank with turning crank attached rotatably mounted on said casing in alignment with the flour agitators, and a pitman bar pivotally connected between said drive crank and the crank bar, capable of oscillating all of the connected agitators back and forth over their respective cup sieves as the turning crank is rotated.

ARTHUR L. CLARK. 

